Design support for overlapping repository paths across review profiles

[rianjs]

Problem

Today repository_profiles are exclusive: a GitHub host/namespace/repo route resolves to one profile. That works for unambiguous automatic profile selection, but it does not support a common workflow where the same repository path should be reviewable by multiple profiles.

Motivating example:

• codex-rianjs-bot and claude-rianjs-bot may both be valid ways to review github.com/open-cli-collective/* and github.com/rianjs/*.
• The user may switch between them based on quota, model preference, or wanting different model perspectives.
• A profile is more than just an LLM runtime: it also selects reviewer entity, repository access, review policy, agent sources, and model mapping. So an LLM-only override is not the right abstraction for this workflow.

Desired direction

Explore support for overlapping repository paths across multiple review profiles, with explicit --profile as the primary disambiguation mechanism.

For example, this should be a plausible user workflow:

cr review https://github.com/open-cli-collective/codereview-cli/pull/359 --profile codex-rianjs-bot
cr review https://github.com/open-cli-collective/codereview-cli/pull/359 --profile claude-rianjs-bot

In this model, --profile should select the full review profile, including reviewer entity and review policy, not just the LLM runtime.

Open design question

The intentionally unresolved part is what cr review <PR> should do when no --profile is specified and multiple profiles match the same repository path.

Do not assume a design yet. Options to evaluate may include:

• fail fast with a clear ambiguity error and list matching profiles
• introduce an explicit preference or default-selection field
• keep exclusive automatic routing but add separate profile eligibility metadata
• another model that preserves predictability without making hidden defaults too surprising

This issue should not lock in a default or tie-break behavior before the UX is agreed.

Acceptance criteria for design

• Clarify the durable config model for overlapping repository paths.
• Define how explicit --profile interacts with overlapping routes.
• Decide and document the no---profile ambiguity behavior before implementation.
• Preserve the invariant that the selected profile controls reviewer entity, repository access, review policy, agent sources, and LLM runtime.